The short answer
For a local blockage you can often clear it yourself: try a plunger, hot (not boiling) water with washing-up liquid, a drain snake or rods, or a proprietary drain unblocker used to the label. Avoid mixing chemicals and don't pour boiling water down plastic pipes. If the blockage is in an outside drain, sewage is backing up, or it returns quickly, stop and call a vetted drainage engineer.
Plenty of household blockages clear with simple tools. The skill is knowing which ones are safe to tackle and recognising the point where DIY makes things worse.
Safe DIY kit
- Plungersinks, basins, toilets
- Drain snake / rodsreaching further blockages
- Hot water + detergentfat in kitchen drains
- Drain unblockerused strictly to label
- Gloves & carealways with waste water
Methods that often work
- Plunger: cover the overflow, plunge firmly over the plughole.
- Hot water + washing-up liquid: good for fat in kitchen drains (hot, not boiling, for plastic pipes).
- Drain snake or rods: for blockages further along the run.
- Proprietary unblocker: follow the label exactly and never mix products.
When to stop and call someone
- The blockage is in an outside drain or manhole.
- Sewage is backing up or there's a foul smell.
- It clears then returns within days.
- Several fixtures are affected at once.
These point to a deeper fault that needs rodding, jetting or a camera — not another bottle of unblocker.
DIY not shifting it?
We'll match you with a vetted, insured drainage engineer who can clear it properly and tell you if there's an underlying cause.
Frequently asked questions
Does baking soda and vinegar unblock drains?
It can help shift minor build-up and odours in a sink, but it rarely clears a real blockage. For anything stubborn, a plunger, rods or a professional is more reliable.
Can I pour boiling water down the drain?
Hot water helps with fat, but boiling water can damage or loosen plastic pipe joints. Use hot rather than boiling water for plastic waste pipes.
When should I stop trying myself?
Stop if the blockage is outside, sewage is backing up, several fixtures are slow, or it returns quickly. These mean a deeper fault that needs a drainage engineer.
Sources & further reading
Figures on this page are typical UK ranges drawn from published cost guides and are intended as guidance, not a quotation.